Clinical correlates

Question 1

Why might someone have dysphagia (difficulty swallowing) or speaking (dysarthria)?

Answer 1

Retropharyngeal abscess, a bulge in the pharynx

Question 2

Why would the external jugular vein be prominent?

Answer 2

Heart failure
SVC obstruction
Enlarged supraclavicular lymph nodes
Increased intra-thoracic pressure

Question 3

How do postsynaptic sympathetic fibers from the cervical ganglia reach the cervical spinal nerves, the thoracic viscera, the viscera of the neck, and the intracranial cavity?

Answer 3

Cervical spinal nerves: gray communicating rami
Thoracic viscera: cardiopulmonary splanchnic nerves
Viscera of the neck: cephalic arterial branches
Intracranial cavity: vertebral and carotid arteries

Question 4

Why do ipsilateral vasodilation and anhydrosis in the face and neck occur after unilateral sympathetic trunk injury?

Answer 4

Vasodilation and absence of sweating on the face and neck (anhydrosis), caused by lack of a sympathetic (vasoconstrictive) nerve supply to the blood vessels and sweat glands

Question 5

How do thyroglossal duct cysts develop and where are they typically located?

Answer 5

Remnants of thyroglossal duct

Located near or just inferior to hyoid bone

Question 6

Why are the inferior parathyroids susceptible to ectopic location in the thymus?

Answer 6

Inferior parathyroids are pulled caudally by thymus but need to leave and join the thyroid. If they don’t, ectopic shit happens

Question 7

What are lateral cervical cysts?

Answer 7

Remnants of cervical sinuses when 2nd pharyngeal arch fails to grow over 3rd and 4th pharyngeal arches

Question 8

How are lateral cervical cysts and thyroglossal cysts distinguished during physical examination?

Answer 8

Location

Thyroglossal cysts near hyoid bone, cervical cysts below angle of jaw or along SCM

Question 9

How are thyroglossal cysts and cancerous thyroid nodules distinguished?

Answer 9

Thyroglossal cysts are attached to tongue, so they move when tongue is protruded. Cancerous thyroid nodules don’t move

Question 10

What is a goiter?

Answer 10

Nonspecific term for chronic enlargement of the thyroid

Question 11

Why does hypertrophy of the follicular epithelium occur with Graves disease?

Answer 11

Autoimmune disease, antibodies to TSH receptor on follicular cells, activating them

Question 12

What is the usual cause of primary hyperparathyroidism and why do kidney stones result?

Answer 12

Usually due to an adenoma of one or more parathyroid glands

Excessive production of PTH in this disorder leads to hypercalcemia because of increased osteoclastic activity of bone

Question 13

Why can thyroidectomy be fatal?

Answer 13

Atrophy or inadvertent surgical removal of all the parathyroid glands results in tetany, a severe neurologic syndrome characterized by muscle twitches and cramps

Question 14

Why do infants have large calvaria and rudimentary development of the face?

Answer 14

Large size of the calvaria in infants results from precocious growth and development of the brain and eyes
Smallness of the face results from rudimentary development of the maxillae, mandible, and paranasal sinuses (air-filled bone cavities), the absence of erupted teeth, and the small size of the nasal cavities

Question 15

Why is the loose connective layer the “danger area of the scalp”?

Answer 15

Pus or blood spreads easily in it

Question 16

Why is the facial nerve susceptible to injury during forceps delivery of a newborn?

Answer 16

There are no mastoid and styloid processes at birth, so the facial nerve is vulnerable

Question 17

Why does TMJ dislocation typically occur anteriorly rather than posteriorly and which nerves are most susceptible to injury?

Answer 17

Posterior dislocation is uncommon, being resisted by the presence of the postglenoid tubercle and the strong intrinsic lateral ligament
Facial and auriculotemporal nerves

Question 18

Where is the injection site for a mandibular nerve block and what regions are anesthetized?

Answer 18

Anesthetic agent is injected near the mandibular nerve where it enters the infratemporal fossa
Usually anesthetizes the auriculotemporal, inferior alveolar, lingual, and buccal branches of CN V3

Question 19

How can severe infections of the ethmoidal cells cause blindness?

Answer 19

If nasal drainage is blocked, infections of the ethmoidal cells may break through the fragile medial wall of the orbit
Also some posterior ethmoidal cells lie close to the optic canal, which gives passage to the optic nerve and ophthalmic artery